VOCATIONAL TRAINING SEMINAR BY :SHIKHA THAPA BTECH FINAL YEAR CHEMICAL ENGINEERING INSTITUTE OF TECHNOLOGYGURU GHASI DAS UNIVERSITYTRAINING TAKEN AT ONGC ACADEMY,DEHRADUN2015 PROJECT CO-ORDINATORDR. R.K. MITTAL CHIEF GEOCHEMIST ONGC ACADEMY, DEHRADUN

TOPIC:DRILLING FLUIDS

About ongc What is drilling fluids? Complete process of circulation of d/fluids Functions Categories Selection criteria Properties of d/fluid

Content

HISTORY Set up under the leadership of Pandit Jawaharlal

Nehru Pandit Nehru reposed faith in Shri Keshav Deva

Malviya who laid the foundation of ONGC in the form of Oil and Gas division, under Geological Survey of India, in 1955.

INTRODUCTION

Oil and natural

gas directorat

e

Oil and natural

gas commissi

on 1956

Converted to

Corporation

1994

Crowned as

navratna 1997

Then maharatna 2010

ONGC is an multinational company with headquarters in dehradun .psu under the oil and natural gas ministry

72% contribution to India’s total production of crude oil and 48% of natural gas. ONGC has established more than 7 Billion Tones of in-place hydrocarbon reserves in the country.

produces more than 1.27 million Barrels of Oil Equivalent (BOE) per day.

It also contributes over three million tons per annum of Value-Added-Products including LPG, C2 - C3, Naphtha, MS, HSD, Aviation Fuel, SKO etc.

About ONGC

68.94% equity stake

Operating 26 sedimentary basins and 11000km pipeline .

International subsidy ongc videsh doing projects in more than 20 countries

discovered 6 of the 7 commercially producing oil basins.

About ONGC cont…

Chemical decay

microorganism

Time

Crude oil

Drilling fluid is used to aid the drilling of boreholes into the earth. Often used while drilling oil and natural gas wells and on exploration drilling rigs

What is Drilling fluids ??

Remove cutting from wells Suspend and release cutting Control formation pressure Seal permeable formations Maintain wellbore stability Minimizing formation damage Cool, lubricate and support the bit and drilling assembly Transmit hydraulic energy to tools and bit Ensure adequate formation evaluation Control corrosion(acceptance level) Facilitate cementing and completion Minimize environment effect

Functions of drilling fluids

Categories of d/f

DrillingFluids

Water based mud

Dispersed

Non dispersed

Oil based mud

Synthetic based mud

Pneumatic drilling fluids

Air or gas only Foam

Additives of water based drilling fluids Viscofiers and filtration loss reducers Bentonite,attapulgite clays,asbestos,CMC etc. Weighting material Calcium carbonate, barytes, hematite, galena etc. SaltsNaCl, KCl, CaCl2 Thinners Chrome lignosulphonate, cutch, modified tannins etc. Chemicals for pH controlCaustic soda, lime, soda ash etc Other chemicals PHPA, sulphonated asphalt,drilling detergent etc.

Composition of a typical bentonite gel water based mud ,density 1300kg/m3. Components added to 1 barrel of water : (bbl=barrel, ppb=pounds per barrel); CMC :(carboxymethylcellulose)

composition

Quantity Mass(kg) Volume (L)

%mass %volume

Water 1bbl 159 1588.99 65.33 84.92

Bentonite 20ppb 9.1 9.07 3.73 4.87

Caustic soda

0.5ppb 0.23 0.22 0.9 0.12

Soda ash 0.5ppb 0.23 0.10 0.9 0.5

High viscosity cmc

1.5ppb 0.68 0.47 0.28 0.25

Low viscosity cmc

3.5ppb 1.59 1.09 0.65 0.98

Barite 160ppb 72.58 17.28 29.82 9.23

Formation pressure Formation temperature Lithology Connate water encountered during drilling Availability of soft water Economics

Selection criteria for D/fluids

Density(specific gravity):mud density is used for providing hydrostatic pressure to control well for drilling

Viscosity define as internal resistance to fluid flowo Funnel viscosity : it is time , in seconds for one quartz of mud flow through a

marsh funnel which has a capacity of 946 cm3.o Plastic viscosity: plastic viscosity is derived from the 600 rpm reading minus

the 300 rpm reading and PV is in centipoise . A low PV of mud is capable of drilling rapidly.

Yield point :physical meaning is the resistance to initial flow or the stress required starting fluid movement. Calculated from 300rpm-600rpm viscometer dial reading by subtracting PV from the 300 rpm dial . Its the ability to lift cutting .

Filtration loss :it determines the rate at which the fluid is forced from the filter press containing the mud sample under specified conditions of pressure and time

Ph :this value tells the acid of drilling fluids Gel strength: The gel strength is the shear stress of drilling mud that is

measured at low shear rate after the drilling mud is static for a certain period of time . its is the ability of fluid to suspend fluid while mud is in static condition.

Properties of drilling fluid

Rheology of drilling fluids

Questionnaire!!!!

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